1. Field of the Invention
The present invention relates to an image pickup apparatus comprising an image pickup device that corresponds to an additive reading function for a pixel output, wherein normal reading and additive reading can be used in accordance with a situation.
2. Description of the Related Art
In an image pickup apparatus such as a camera, there is a problem that an image is shaken due to camera shake or object shake during exposure, and a blurred image is generated. As countermeasures against shake of such an image, in Jpn. Pat. Appln. KOKAI Publication No. 8-223471 or Jpn. Pat. Appln. KOKOKU Publication No. 8-15316, there is proposed a technique of moving an optical system or an image pickup device so as to eliminate motion of an image caused by camera shake, thereby preventing a blurred image. In addition, there is known a technique of increasing a shutter speed and reducing an effect of shake while amplifying an output of the image pickup device by means of an amplifier circuit or the like to increase imaging sensitivity. Further, in the case where a high definition image pickup device for still image pickup is applied to motion image pickup, for example, in Jpn. Pat. Appln. KOKAI Publication No. 2004-222130 or the like, there is known a technique of adding (mixing) pixels of the same color in an analog manner by predetermined number in the image pickup device, and then, reading an output after adding, for the purpose of increasing imaging sensitivity and reducing a read time.